1. Field of the Invention
The present invention relates to a fluid tank valve, particularly a hydraulic refill valve, especially adapted for use in controlling the level of a liquid within a tank.
2. Description of the Prior Art
Hydraulic valves have been used for many years for controlling the level of a liquid within a tank. Such valves are widely utilized in the plumbing industry, particularly in regulating the flow of water into the tank of a toilet, sometimes termed a water closet. Conventional valves of this type, often called ballcock valves, are described, for example, in U.S. Pat. Nos. 3,429,333 and 4,100,928.
While some changes have been made in the construction of ballcock valves throughout the years, the operating mechanisms of conventional, commercially available ballcock valves sold for use in toilets have remained largely standardized for many years. For example, ballcock valves similar to the type described in U.S. Pat. No. 4,100,928 are widely sold throughout the United States and elsewhere by Fluidmaster Inc., located at 30800 Rancho Viejo Road, San Juan Capistrano, Calif. 92675 as the FLUIDMASTER(copyright) 400A fill valve.
Conventional valves of this type are typically mounted in the tank of a toilet. An upright fluid supply tube extends upwardly from a hollow mount located on the bottom of the tank at the fluid inlet. The fluid supply tube terminates in a fluid supply outlet at its upper extremity which opens into a valve enclosure. A resilient, flexible diaphragm is mounted within the valve enclosure and is secured relative to the enclosure about its periphery. The diaphragm has a central, tubular core with a vertical passage defined therethrough. Lower and upper sealing rings are located at the lower and upper ends of the diaphragm core and project radially inwardly into a longitudinal passage through the core at the lower and upper ends of the core, respectively. An intermediate sealing ring projects radially inwardly into the longitudinal passage between the upper and lower ends of the diaphragm core. One or more bleed apertures extend radially through the wall of the diaphragm core. The bleed apertures provide a flow path between the central, axial, longitudinal passage within the confines of the core and a back-pressure chamber located above and exteriorly of the diaphragm body and within the confines of the structures forming the valve enclosure.
A metering pin extends longitudinally down the center of the diaphragm core passage. The metering pin includes radially enlarged sealing portions separated by radially reduced portions. The metering pin is raised and lowered by a valve lever arm coupled to a float so that, when the water level in the tank rises, the valve lever is actuated to lower the metering pin to a position in which one of the radially enlarged portions of the metering pin blocks the valve passage at the upper sealing ring. A limited flow of water is then permitted up through the lower sealing ring and past the intermediate sealing ring through the bleed apertures to the back-pressure chamber. Pressure is thereby allowed to build up in the back-pressure chamber, which then closes the body of the valve against a valve seat at the fluid supply outlet. This blocks flow from the fluid supply tube to outlet ports in the valve, thus shutting off the flow of water into the tank.
When the toilet is flushed the float drops due to the falling water level within the toilet tank. This action operates the valve lever arm, raising the metering pin which then unblocks the upper sealing ring. The back-pressure chamber is thereby vented to atmosphere through the bleed apertures. The pressure of water from the fluid supply tube thereupon forces the body of the valve up from the valve seat, thereby permitting the flow of water from the fluid supply tube to the valve outlet ports. This fluid flow ultimately fills the tank, whereupon the float rises to operate the actuating lever arm to again lower the metering pin. With the upper sealing ring again blocked, pressure rebuilds in the back-pressure chamber to again force the body of the valve into a sealing relationship with the valve seat.
The longitudinal fluid passage within the diaphragm core is quite small, and the annular orifices around the metering pin are even smaller. Consequently, even very tiny particulates of sediment, sand, scum, or dirt can cause a blockage within the valve orifices, central passage, or bleed apertures through the wall of the core. The valve will thereafter operate improperly until repaired or replaced.
Clogging of the valve passage is particularly likely since at least a portion of the passage through the core is open to fluid when the metering pin is reciprocated to unseat the body of the valve from the valve seat. At this point in the operation of the valve there is a considerable onrush of water directed straight up into the passage. Consequently, it is not at all unusual for small particles of sediment or grit to enter the lower portion of the passage through the diaphragm core when the body of the valve is unseated. Such particulate matter is then very likely to lodge within the flow pathways through the core of the diaphragm as it is carried by the water passing into and through the diaphragm.
Another problem that has persisted in the operation of conventional ballcock valves is the rather lengthy fill time and noisy operation of the valve, particularly as it approaches a closed condition. This problem occurs due to the inordinately long lever arm that is utilized to manipulate the metering pin. Because of the long lever arm, the enlarged portion of the metering pin that seals against the upper sealing ring approaches the upper sealing ring quite slowly. As a consequence, the rate at which pressure builds up in the back-pressure chamber rises progressively, but very slowly, thus lengthening the time required for sufficient pressure to build up in the back-pressure chamber to seat the body of the diaphragm against the valve seat. During this time there is an annoying hissing noise due to the slow passage of water past the metering pin and through the upper sealing ring.
One of my prior patents, U.S. Pat. No. 3,729,017, incorporated herein by reference in its entirety, addresses this problem. The system described in this patent allows the lever arm operating the metering pin to be shortened considerably by the utilization of an inverted, cup-shaped float disposed atop the valve. The lever arm that operates the metering pin described in this patent is enclosed entirely within the confines of the cup-shaped float. The length of the lever arm is thereby greatly reduced from other conventional ballcock valves. When the water level in the tank drops, the roof of the cup-shaped float bears downwardly on the distal end of the lever arm, thereby forcing it downwardly to operate the metering pin in a desired direction. When the level of water within the tank rises, it lifts the float with it, thus relieving the downward pressure of the roof of the float against the distal end of the lever arm. A spring thereupon urges the distal end of the lever arm upwardly, thereby moving the metering pin in the opposite direction.
While the foregoing system does have the desired effect of reducing the fill time and the duration of the noisy operation of the valve as it nears closure, there is no convenient means for making adjustments so that the valve is actuated at a selected level of water in the tank. Such adjustments are important due to the many variations in the height at which the valve is mounted above the bottom of the tank, the height to which the overflow pipe extends above the bottom of the tank, and other variations in ballcock valve configuration that require small, but important adjustments in the level of water in the tank at which the valve is operated. The improved valve of the present invention provides a simple, but novel solution to this problem.
A further problem that exists in the conventional construction of ballcock valves is that the height adjustment mechanisms employed to vary the height at which the valve is mounted above the floor of the tank allow the components of the upright fluid supply tube to become totally separated from each other. The upright fluid supply tube and its mounting assembly are typically formed of telescoping members having a seal therebetween. A clamping mechanism is provided to allow the telescoping members to be adjusted and secured in fixed relationship to each other. I have described one such coupling mechanism in my prior U.S. Pat. No. 4,122,862, which is also incorporated herein by reference in its entirety.
However, I have since discovered that it is all too easy for the component telescoping members of the fluid supply tube and its tank bottom mount to become totally separated from each other while the installer adjusts the height of the valve above the bottom of the tank. Thus, during installation the installer is likely to find that the upper portion of the upright fluid supply tube has become completely detached from the lower portion that is mounted to the bottom of the tank. The necessity for reconnecting these members thus represents an annoyance and lengthens the time required to perform the installation of the ballcock valve. However, by providing a simple but important modification to the system of my prior U.S. Pat. No. 4,122,862 this problem can be completely avoided.
The unique fluid tank valve assembly and the refill valve construction of the present invention provide novel and useful solutions to all of the foregoing problems hereinbefore identified, as well as other advantages in the field of fluid valves, particularly hydraulic valves.
In one broad aspect the present invention may be considered to be a fluid tank valve assembly comprising: a tank having a bottom; an upright fluid supply tube projecting upwardly relative to the bottom of the tank; a tank refill valve located atop the fluid supply tube and having at least one outlet port to the tank therefrom and operable between a valve seating position blocking fluid flow from the fluid supply tube to the outlet port and a valve unseating position permitting fluid flow from the fluid supply tube to the outlet port; a float lever assembly located atop the refill valve and having a lever arm movable between a raised position to operate the refill valve to one of the valve seating and unseating positions and a lowered position to operate the valve to the other of the valve seating and unseating positions; an inverted, cup-shaped valve actuating hood disposed atop the valve lever assembly, wherein the valve actuating hood has a roof and a skirt depending from the roof and surrounding the refill valve; and a buoyant float engaged with the skirt of the valve actuating hood and adjustably positionable along the skirt to a selected distance from the roof, whereby the roof of the valve bears downwardly against the lever arm to force said lever arm to the lowered position until fluid level in the tank rises sufficiently to cause the float to lift the valve actuating hood and move the lever arm to the raised position.
The foregoing construction represents a feature of the present invention that is a significant improvement over my prior U.S. Pat. No. 3,729,017. In that prior patent, I utilized a cup-shaped float that rotated the lever arm which operates the refill valve mechanism. However, in that prior patent there was no system for easily adjusting the level of water in the tank at which valve actuation would occur.
According to the present invention I have modified the prior system by replacing the inverted cup-shaped float that operated the valve lever arm directly, with a cup-shaped hood that is not buoyant and which is not raised or lowered directly by a change of water level in the tank. However, I have attached to this hood a float that can be secured to the hood at a selected longitudinal position relative thereto. A spring may be provided to bias the float lever arm toward the raised position,
Preferably, the skirt of the hood has a cylindrical, annular shape and the float also has an annular configuration and is disposed about the skirt in contact therewith. Preferably also, the float includes a plurality of radially inwardly protruding projections, such as longitudinally extending ribs, that contact and reside in frictional engagement with the outer surface of the skirt. The longitudinal position of the float relative to the hood may be adjusted by overcoming the frictional force and sliding the ribs longitudinally toward the transverse roof so that the float will lift the hood, thus moving the valve lever arm to its raised position, only when the water within the tank has risen to a relatively high level. Conversely, by overcoming the force of friction and sliding the float longitudinally toward the lower, open end of the skirt, a relatively low level of water within the tank will raise the float, thereby causing the lever arm to be pushed to its raised position. Infinitely variable adjustments to the refill valve actuating level of water within the tank may thereby be performed in this manner.
In another broad aspect the invention may be considered to be the construction of the refill valve itself. The refill valve of the invention is comprised of an upright fluid supply tube; a flexible, resilient, annular valve diaphragm; a metering pin; and a float lever assembly. The upright fluid supply tube terminates in a fluid supply outlet at its upper extremity. The diaphragm is housed within a valve enclosure atop the fluid supply outlet and is operable to alternatively seal and unseal the fluid supply outlet. The diaphragm has a central, annular, tubular core that defines a longitudinal passage therethrough. The diaphragm core has upper and lower ends and defines a lower sealing ring at its lower end, an upper sealing ring at its upper end, and an intermediate sealing ring located between the upper and lower ends. The lower, upper and intermediate sealing rings project radially into the longitudinal passage of the core. The diaphragm core further defines at least one bleed aperture, and preferably diametrically opposed bleed apertures, located between the upper and intermediate sealing rings. The bleed aperture or apertures extend radially through the core.
The metering pin is disposed in the longitudinal passage and has a plurality of radially enlarged sealing portions and radially reduced portions arranged longitudinally thereon. The float lever assembly is coupled to the metering pin and is operable to alternatively advance and retract the metering pin in the longitudinal passage. The metering pin is movable to a valve unseating position in which the enlarged sealing portions of the metering pin reside in sealing engagement with the lower and intermediate sealing rings of the diaphragm while the radially reduced portions permit fluid flow through the bleed aperture or apertures and out of the upper end of the longitudinal passage so that the diaphragm unseats the fluid supply outlet. Alternatively, the float lever assembly is operable to move the metering pin to a valve seating position in which one of the enlarged sealing portions of the metering pin resides in sealing engagement with the upper sealing ring while the radially reduced portions of the metering pin permit metered flow of fluid from the supply tube outlet past the lower and intermediate sealing rings and through the bleed aperture or apertures so that the diaphragm seals the fluid supply outlet.
The diaphragm employed in the refill valve of the invention is the same diaphragm that is employed in the conventional FLUIDMASTER(copyright) 400A fill valve. This diaphragm is largely depicted and described in prior U.S. Pat. Nos. 3,429,333 and 4,100,928, but may be modified. The metering pin employed, however, differs significantly from the metering pins utilized in these prior art ballcock valves.
Specifically, and unlike the prior, conventional ballcock valves described, the metering pin of the present invention is configured to simultaneously seal both the lower and intermediate sealing rings when the valve lever arm actuates the valve to its unseated position. Unlike prior systems, the lower portion of the longitudinal passage through the core of the diaphragm is thereby closed both at the intermediate sealing ring in the diaphragm core beneath the bleed apertures and at the lower sealing ring during the time that there is a significant liquid flow from the upright fluid supply tube past the valve seat. Consequently, and because this portion of the longitudinal passage is totally closed, dirt, sediment, particulate matter, and scum cannot enter into that portion of the passage during the time that a large volumetric flow of liquid through the valve occurs. As a result, the refill valve of the present invention is far less likely to clog than conventional, prior ballcock valves of this type.
Still another aspect of the invention resides in the coupling system employed for the hollow, upright fluid supply tube leading to the refill valve. The coupling is secured to the bottom of the tank at a fluid inlet thereto and includes a hollow, cylindrical, annular mount for attachment to the fluid inlet at the bottom of the tank. The hollow mount defines a lower, internally threaded barrel and a cavity beneath the barrel having a diameter greater than the interior diameter of the barrel. A downwardly facing annular ledge is formed between the internally threaded barrel and the cavity. The lower end of the upright fluid supply tube has external threads and is threadably engaged in the barrel.
According to the improvement of the invention the lower extremity of the supply tube is configured with a catch that when unrestrained, extends radially outwardly beyond the external threads on the lower end of the fluid supply tube. The catch is resiliently deflectable radially inwardly to pass through the barrel as the lower end of the supply tube is threadably advanced into the barrel. The catch springs outwardly upon entering the cavity in the mount, whereby the catch and the ledge interact to prevent complete separation of the supply tube from the mount while permitting longitudinal adjustment therebetween.